March 29, 2000
Genetics and Heredity
Question from Canada:
What is the probability of a IDDM male, diagnosed at the age of ten, having diabetic children in his middle to late twenties? Is there any way to determine if Type 1 is caused by heredity or environmental factors? In this particular case, this man had chicken pox and measles before diagnosis of Type 1 diabetes (so an environmental cause seems plausible). Can amniocentesis or other prenatal screening tests show predispositions to Type 1?
Answer:
In all cases of Type�1A (autoimmune) diabetes both genetic and environmental factors are involved; but the history of chickenpox and measles is almost certainly irrelevant. The chances of a father with Type 1 having children with the same problem are a little over 6% for a Caucasian in North America. Amniocentesis could confirm susceptibility but the small risk would not be justified as the information could be obtained on cord blood.
DOB
